A half-goblin is a cross-breed between a goblin, whose ancestry accounts for their diminutive size, and a human. It is unknown if goblins can breed with Muggles, but since very few Muggles ever become aware that goblins exist, this is a remote possibility. The only known part-goblin, Filius Flitwick, is trained in the human magical arts, as shown by his carrying a wand, having attended Hogwarts and teaching there. It is not impossible that, properly trained, they command a number of goblin magical arts, but, if so, it is likely for full goblins to be unwilling to provide such training, effectively preventing their part-human offspring from performing their kind of magic. Many half-goblins benefit from intelligence and wit inherited from their Goblin ancestors. An example is again Filius Flitwick who was sorted into Ravenclaw house at Hogwarts School of Witchcraft and Wizardry, was a "model student" during his time there and eventually returned to the school to teach.

It is possible that certain spells and potions do not work on Half-goblins. For instance, it is unknown if Half-goblins can use Polyjuice Potion as this particular potion is designed for human transformations only, and therefore does not work on other beings. For instance, Polyjuice Potion is useless to any Half-Giant. However, because the potion is known to be effective on Part-Veelas, if their Veela ancestry goes back at least two generations, it is likely to for any Half-goblin whose goblin ancestor is not their mother or father.

As half-breeds, half-goblins fall into the same prejudices that other half-breeds suffer. Dolores Umbridge was renowned for and later punished for crimes against half-breeds.